A growing body of research shows that the out-of-school activities and arrangements that adolescents experience have important implications for their academic, social, and physical development. Although summertime represents the largest consecutive period of out-of-school time - accounting for nearly one-quarter of adolescents'developmental experiences during a calendar year - very little is known about the basic arrangements and activities that youth experience during the summer months. Likewise, a paucity of research is available concerning the implications of summertime experiences for adolescents'physical health, school adjustment, and psychosocial development. Drawing from interdisciplinary theory and research, the primary goals of the proposed study are: 1) to develop knowledge about basic care arrangements and activities that adolescents experience during the summertime (e.g., self care, parent/relative care, organized activity participation, paid employment) and, 2) to assess relations between these summer experiences and broad indicators of adolescent adjustment during the following school year. Moderating factors and mediating processes are of interest. The investigation proposes secondary data analysis of Wave 2 of the Child Development Supplement (CDS) to the Panel Study for Income Dynamics (PSID). The PSID-CDS-II includes a nationally representative sample of 1,468 adolescents (ages 12- 18) from 1,179 families. Data for Wave 2 were collected during 2002-2003. At that time, the median family household income for the sample was = $50,010 and 16% of the families were at or below the federal poverty threshold. The gender and racial/ethnic status of the participating youth were: Male (50%), White (47%), Black or African American (42%), Hispanic or Latino (6%), Asian (1%) and American Indian or Alaskan Native (.6%). Information on adolescents'summertime activities and arrangements as well as multiple indicators of their adjustment during the following school year (e.g., body mass index/obesity, academic achievement, psychological/emotional well-being, social behavior problems) was provided through adolescent- and parent-reports. Results will begin to address the knowledge gap on conditions under which adolescents'summertime experiences may provide risks and opportunities for the development of physical health, social-emotional, and academic competencies. Relative to the school year, the summer months represent a time of heightened risk for many adolescents with respect to antisocial and criminal behaviors, weight gain and obesity, and declining academic achievement. At the same time, research indicates that when adolescents'out-of-school time involves participation in organized activities and supervised arrangements, the likelihood of developing these adjustment problems is reduced and the development of physical health and social-academic competencies are augmented significantly. Accordingly, the proposed study will help to clarify the summer activities/arrangements that are likely to play a role in the development of problematic developmental outcomes as well as those associated with the promotion of positive youth development.